Exposure devices which perform exposure of resist include light exposure devices and electron beam exposure devices. Of these, electron beam exposure devices do not require the use of reticles as with the case of light exposure devices, allowing the time and cost involved in fabricating the reticle to be eliminated, which is suitable for small-lot production as in the case of engineering samples.
Such electron beam exposure devices use what is known as “block exposure”, in which multiple mask patterns used frequently are formed as a block mask, and the multiple mask patterns are exposed in batch fashion, to improve throughput.
However, finer design of semiconductor devices has led to finer patterns, which may result in incident electrons to adjacent mask patterns scattering within the resist, with the completed resist pattern form not being able to realize the target form due to the so-called “proximity effect”.
One attempt to suppress this proximity effect is to adjust the position of the sides of the mask patterns arrayed in the block mask so as to prevent the adjacent mask patterns from affecting one another. However, with this method the mask patterns of the block mask become unusable for other types of exposure objects in the event that the type to be exposed is changed, meaning that a different block mask has to be used for each type, which defeats the advantage with regard to time and cost.
Another attempt to suppress the proximity effect is to indiscriminately reduce the size of the mask patterns arrayed in the block pattern. However, the proximity effect affects different portions on the masks in different ways, so simply indiscriminately reducing the size of the all of the mask patterns may not be able to suppress the proximity effect at all of the masks.
On the other hand, there is also a method for performing auxiliary exposure for supplementing exposure of portions where the proximity effect is small and exposure is insufficient. With this method, a mask pattern within a block mask is finely divided into small regions, auxiliary exposure amount appropriate for each small region is calculated, and auxiliary exposure is performed for each small region. However, a great amount of time is required for calculating the auxiliary exposure, and further, a great deal of resources within the calculator for performing the calculations, such as memory, is occupied. Moreover, this method is also disadvantageous in that the number of shots increase due to the auxiliary exposure, and the throughput of the electron beam exposure device decreases.
Also, there is a method in which the effects of scattering electrons on the resist is taken into consideration, and in the event that there is a mask pattern in an already-existing block mask which is close in form to the target resist pattern, that mask pattern is used to perform exposure. However, with this usage, proximity effect between adjacent mask patterns is not taken into consideration, so in the event that the proximity effect is great, the form of the completed resist pattern form is not able to realize the target form.
Thus, there is demand for a charged particle beam exposure method wherein exposure data is corrected taking the proximity effect into consideration.